Why do i hum randomly?

Often, ADHD stimming looks similar to the repetitive verbal stims and stereotyped movements performed by people with autism spectrum disorder (ASD).

ASD is a spectrum of conditions that affect speech and nonverbal communication.

Some vocal stims associated with ASD include shrieking, humming, and echoing words or phrases from books or movies.

A 2017 analysis of the relationship between ADHD and ASD found that up to 65% of children with ADHD have clinical symptoms of ASD. Treatment options for both conditions may also overlap.

One observation the analysis explores — though more research is needed — is that the condition overlap may support the theory ADHD is a mild subset of ASD.

Tourette syndrome (TS) is a severe tic disorder that develops at a young age. While tics are repetitive movements that look like stims, the experience of tics is different.

Tics usually onset with a precursor feeling, generalized or local to one body part.

While ADHD does not cause tics, one systematic review finds:

People hum for several reasons, such as to calm nerves, feel happier and reduce stress. People hum unconsciously and consciously. Many use humming as a simple and effective way to ease tension and reduce stress and often derive health benefits in the form of improved sinus health in the process.